The facts are Westerners chose their Carbines and rifles based more on availability of ammo. The most available cheap ammo was from Military forts. The .45 Colt and .45-70 etc were very popular.
The use of matching ammo for handgun and carbine is some what over rated.
My affinity for pairing a levergun and a revolver in the same round has more to do with frugality than with what people in the 19th century west may or may not have done.
From the perspective of a handloader, I only have to buy one set of dies to assemble ammo for a long gun and a handgun, Invest in one kind of brass, and I'm sure with some research and experimentation, I can come up with a load that shoots well in both a rifle and a revolver, meaning that I can do well with one type of bullet and one type of powder for two firearms.
Additionally, I like the versatility of revolver rounds within their range limitations. Most of what I'm going to be doing is informal target shooting, so a general purpose load for both guns will suffice 99% of the time. In the unlikely event I get to go hunting again (I'm indefinitely stuck in the bleak, soul crushing wasteland of Sacramento, CA) I can ramp things up and kill almost all north American game out to 100 yards or so, or dial things down so I can poke a hole in small game without evaporating the critter.
Additionally, with draconian new ammo laws taking effect in California at the start of 2018 (we'll have to obtain purchase permits and pass a background check every time we buy ammo) I want a streamlined selection of chamberings in my safe so I only have to focus on stockpiling and reloading for a few rounds. I'm not paying to play the game of jumping through the state's hoops to buy ammo.
As far as whether to go with a .44 mag or .44 spcl. revolver, practicality is pushing me to the .44 mag. .44 mag revolvers are and brass are way more common and thus it seems more likely I'll find good deal on the used market.